to remove a container that docker doesn't know isn't running:
- take note of the container ID
- service stop docker
- modify the config.json file in /var/lib/docker/containers/$CONTAINER_ID to have "Running":false
- service start docker
- docker rm $CONTAINER_ID
Unfortunately, this makes all the other containers turn into ghosts, so you can only do it when there's only a single container. Plus it's really hacky.